Carbamoylphosphorylguanosine (CPG) in Urine (24-hour collection)
This test measures a chemical marker found in urine over 24 hours that may help assess kidney function, particularly in detecting certain inherited kidney disorders.
["A 24-hour urine test for CPG can help diagnose genetic kidney conditions early."]
Key facts at a glance
- LOINC
- 73484-8
- Short code
- Carbidopa ind plt IgM SerPl Ql FC
- Synonyms
- Carbidopa ind plt IgM SerPl Ql FC
- Category
- hematology
- Sample
- serum
- Container
- Red-top tube (SST)
- Units
- N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- Method
- flow-cytometry
- CPT
- 82784
- Specimen volume
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why This Test Might Be Ordered
Your healthcare provider may recommend this test if you have a family history of inherited kidney diseases, symptoms like frequent urination, kidney stones, or unexplained kidney function concerns. It’s also used in research or specialized genetic testing for conditions like cystinosis or other metabolic disorders affecting kidney function.
What to Expect Before the Test
You’ll need to collect all urine for a full 24-hour period, starting after your first morning urine void. Store the urine in a refrigerator or cool container, and return it to your lab within the specified timeframe. Follow your provider’s instructions precisely to ensure accurate results.
What the Test Measures
CPG is a byproduct of certain metabolic processes in the kidneys. Elevated levels in urine may indicate genetic disorders that impair kidney function or metabolism, though this test alone doesn’t diagnose a specific condition. Results are often interpreted alongside clinical findings and genetic testing.
How the Results Are Used
Results help identify whether genetic factors may be contributing to kidney issues. If elevated, further genetic testing or specialist evaluation may be recommended to determine the underlying cause and guide treatment options.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Elevated CPG levels in urine may suggest inherited metabolic disorders affecting kidney function, such as cystinosis or other lysosomal storage diseases. These conditions can cause progressive kidney damage, so early detection is important for managing symptoms and planning care. Your provider will discuss next steps based on your specific situation, including genetic counseling or referral to a nephrologist.
Short name
Urine CPG Screen
Frequently asked questions
What does a normal result mean?
No, this test is primarily used to screen for specific inherited metabolic disorders affecting kidney function. It does not replace standard kidney function tests like creatinine clearance or urine protein tests, which assess broader kidney health.
Yes, avoid certain medications (like some diuretics) that may affect urine composition. Also, drink enough fluids to maintain normal urine output throughout the 24-hour period, but avoid excessive intake that could dilute the sample.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy